/*
  Storage封装
*/
const STORAGE_KEY = 'mall';
export default{
    //存储值
    // storage.setItem('abc',{a:1},'user')
   setItem(key,value,module_name){
       if(module_name){
           let val = this.getItem(module_name);
           val[key] =value;
           this.setItem(module_name,val)
       }else{
           let val =this.getStorage();
           val[key] = value;
           window.sessionStorage.setItem(STORAGE_KEY,JSON.stringify(val))
       }
        
    },
    // 获取某一个模块下的属性user下面的usaername
   getItem(key,module_name){ 
    if(module_name){
     let val = this.getStorage()
      if(val) return val[key];
    }
    return this.getStorage()[key]
     
    },
   getStorage(){
     return JSON.parse(window.sessionStorage.getItem(STORAGE_KEY) || '{}');
    },
    clear(key, module_name){
      let val = this.getStorage()
      if(val[module_name]){
          delete val[module_name][key]
      }else{
          delete val[key]
      }
      window.sessionStorage.setItem(STORAGE_KEY,JSON.stringify(val))
    }
}